1. Field of the Invention
The invention relates to networking processing modules and peripheral devices in a network connected computer system and more particularly to arrangements for providing information on the specifications of peripheral devices to processing modules using the peripheral devices in a network.
2. Description of the Related Art
In networked computer systems, processing modules and peripheral devices serving the processing modules are connected at different points of a network. The network couples the processing modules with other processing modules and the peripheral devices required to service the processing modules. Each processing module includes a manager that manages one or more peripheral devices servicing processing module applications by sending request messages to an agent at the managed device and receiving data returned from the managed device on status and attributes of the managed device. The messaging through the network may be performed using one of several available protocols. In exchanging data, the processing module application may use one of several different protocol models. If the OSI protocol model is employed, the CMIP management protocol is used for device management. Alternatively, the application may use the TCP/IP protocol model which includes the SNMP management protocol for device management.
U.S. Pat. No. 5,367,635 issued to Neal Bauer et al. on Nov. 22, 1994 discloses a computer network management system in which a user editable text file defining object identifications, object types and the path and name of associated executable software is generated and sent to a managed node. The user can then invoke user defined executable software by sending a network command and a user defined object identifier to the agent in a managed node. Data can then be sent between the user and the user defined executable software at the managed node. In order to manage a network peripheral device, however, the user processing module manager must store information on the characteristics of the device. The managed device characteristics information embedded in the processing module manager by the processing module supplier, however, may not correspond to the current characteristics of the managed device. As a result, the user executable software may not perform the desired functions in the managed device.
U.S. Pat. No. 5,404,532 issued to Wade C. Allen et al. on Apr. 4, 1994 discloses a networked computer system having communication between managers and agents in which an event forwarding discriminator in the agent program discriminates among events at the managed device to notify the manager only of significant events defined by the manager. The event forwarding discriminators are monitored so that if an event forwarding discriminator fails, the agent rebuilds or restores it with all its attributes and the manager is notified. The reconstruction of important portions of an agent, however, does not address the problem of providing a processing module manager with the characteristics of the agent of the managed device.
U.S. Pat. No. 5,278,978 issued to Richard A. Demers et al. on Jan. 11, 1994 discloses an arrangement for exchanging data between heterogeneous database systems by converting data in a receiving database system in which descriptive information exchanged between a sending database system and the receiving database system. In the event that the sending and receiving database systems are dissimilar, the data received in the format of the sending database system is converted to the format of the receiving database system. While the Demers et al. patent permits conversion of data between dissimilar machines, it does not relate to maintaining a managed device description file for the purpose of sending commands and controlling the device with respect to its status and attributes in a network.
Managed device characteristics are generally stored at the processing module manager in the form of a device description file specifying the characteristics of the managed peripheral device.
The description file, generally denoted as an MIB (Management Information Base), for each management protocol is written in a different format. In the SNMP management protocol, the MIB of the manager uses a syntax ASN.1. The CMIP management protocol uses a GDMO having the ASN.1 syntax but having a different format than the ASN.1 syntax for SNMP. In the event that the processing module manager operates under a different management protocol than the managed device, access to the data on the characteristics of the managed device may not be properly parsed by the processing module manager so that generation of a managed device description file at the manager would not be possible.
A description file for a peripheral device is generally supplied with the processing module manager for the application and is of the type corresponding the management protocol of the manager. A peripheral device in the network system, however, may utilize another management protocol so that the description file at the manager is not appropriate for the peripheral device. As a result, request messages from the manager based on the format of the management protocol thereat cannot be parsed by the agent in the managed peripheral device. Further, changes in the peripheral device may not be reflected in the description file supplied to the processing module manager from an outside source and a new peripheral device may be added for which there is no description file in the processing module manager.
If the management protocol of the processing module manager is different than the management protocol of a peripheral device managed by the processing module, data packets between the processing module manager and the agent of the managed device may not be sent with compatible management protocols and the description file at the processing module manager may not be in the required syntax. As a result, it is a problem in networked computer systems that description files of managed devices residing in processing module managers may not be useful in making queries on the status and the attributes of the managed device. Neither of the aforementioned patents address the problem of exchanging management data between processing module managers and managed device agents in a networked computer system having various management protocols.